Living walls (LW) have been widely proposed as a form of green infrastructure to improve aesthetics, energy consumption, and microclimate in urban environments by adding densely-planted vegetation to the outside walls of buildings. Scientific studies using multiple treatments in a single LW face challenges due to the close physical proximity of different treatments, particularly the potential for plants above to influence those below. A study on a west-facing LW was undertaken to investigate 36 unique treatments in Adelaide, South Australia, for nine months. The LW comprised combinations of six native plant species, three soil substrates and two irrigation volumes. The LW consisted of 144 modular trays mounted on a wall in a 12 × 12 grid with four replicates of each treatment. The location of each treatment was designed to account for a cascading carry-over effect that may be present when one plant is placed above another. Carry-over effect of the model designed showed mixed results among the plant groups identified. It was also found that long-form plants can significantly shade smaller plants below them. Experimental research into the performance of plants in mixed species LW should consider the carry-over effect to account for this.

Adsorption using activated carbon that decomposed from agricultural waste has been proven to be effective in removing heavy metals in wastewater. This study was carried out to investigate the adsorption of heavy metals wastewater (Lead) using activated carbon that synthesized from the fruit waste which is jackfruit peel. The efficiency of jackfruit peel activated carbon in removing lead from wastewater has been compared to the commercial activated carbon. Result shows that the commercial activated carbon gave better result as compared to jackfruit peel activated carbon (98% of lead removal for commercial activated carbon and 80% of lead removal for jackfruit peel activated carbon). This can be explained from the characteristics of the activated carbon where the commercial activated carbon has a very well develop pores structures in contrast to jackfruit peel activated carbon. In term of isotherm and kinetic study, the Freundlich isotherm model is better fitted in equilibrium adsorption isotherm for jackfruit peel activated carbon and it is favorable adsorption condition. For commercial activated carbon, the Langmuir isotherm is better fitted to the adsorption of lead and monolayer adsorption capacity was found. The experimental data fitted very well the pseudo second order in kinetic model for both activated carbon where the adsorption controlled by chemisorptions.

Living walls are fast becoming a ubiquitous feature of modern living and are widely implemented in commercial buildings in both internal and external environments. However, there are several challenges associated with maintaining healthy plant growth on these water sensitive urban design systems. This experimental study of an instrumented prototype-scale living wall has found that there is a close relationship between the plants, substrates and adopted irrigation regimes. In this study, plant selection was found to be more critical than either substrate or irrigation regime selection. This research also found that both the location of the plants on the wall and irrigation volume significantly affected the plants’ ultimate total dry weight. In particular, plants were found to grow taller on the upper section of the living wall compared to the middle and lower sections. It is recommended that particular attention should be given to plant location and the amount of irrigation water supplied at different positions on the living wall.

Living walls are becoming a widely used water-sensitive urban design technology that can deliver various economic, social and environmental benefits. One such benefit is to cool the surrounding environment through the process of evapotranspiration. This study measured the evapotranspiration from an instrumented prototype-scale living wall and calculated the resulting evaporative cooling effect. The range of the measured evapotranspiration rates from the living wall was from 41 to 90 mL/mm per plant pot. This equated to latent heat of vaporisation values from 171 to 383 MJ/month/m². This was then compared with the performance of a non-vegetated water-sensitive urban design technology, namely, a porous concrete pavement. For a typical summer month in a warm temperate climate, it was found that a porous concrete pavement system only had between 4 and 15% of the cooling effect of an equivalent living wall.